With reference to agricultural soils, consider the following statements:1.A high content of organic matter in soil drastically reduces its water holding capacity.2.Soil does not play any role in the sulphur cycle.3.Irrigation over a period of time can contribute to the salinization of some agricultural lands.Which of the statements given above is/are correct?

1. A

   1 and 2 only

   (a) 1 and 2 only. Organic matter increases, rather than drastically reduces, water-holding capacity, so statement 1 is false. Soils are active in the sulphur cycle (organic S, sulphate, microbes), so statement 2 is false. This option is not the key.

2. B

   3 only

   (b) 3 only. Prolonged irrigation in arid and semi-arid tracts brings dissolved salts that accumulate when evapotranspiration exceeds leaching—secondary salinisation. That is statement 3, and it is the only correct statement. This option is the official key.

3. C

   1 and 3 only

   (c) 1 and 3 only. Statement 3 is true, but statement 1 reverses the role of humus. This option is not the key.

4. D

   1, 2 and 3

   (d) 1, 2 and 3. Two of the three statements are false. This option is not the key.

Summary. Official key is (b) 3 only. Humus raises a soil’s water-holding capacity, so statement 1 is backwards. Sulphur cycles through soil organic matter and sulphate ions, so statement 2 is false. Irrigation without adequate drainage does salinise land over time, which is statement 3. Only that statement survives. The WRAP key is (b).